z3r0n3 Posted September 5, 2008 Share Posted September 5, 2008 I'm looking into purchasing a custom piston set for my L28, but thought I'd ask for any advice ya'll might have for me before I consider purchasing something like this. My goal for this project is a 14/15:1 compression ratio, for running e85. Engine setup would be carburetted n42/n47, overbore 3mm (89mm), stock l28 rods, stock crank, and hopefully a metal head gasket that's about 1mm. I was looking at some Wiseco pistons that had a 9cc dome, and those about fit the bill, just can't find them to purchase anywhere. A 9cc dome also sounds kind of rediculous, i havn't done much research into those but i think that those might protrude the gasket. Anyone else done something like this? Any advice would be golden. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted September 5, 2008 Share Posted September 5, 2008 YOu need to do lots of mockup with whichever head your going to use. With that desired CR, you need to have TONS of quench in all areas of the head. Lots of clay, and molding substance, to get an EXACT form of each combustion chamber AFTER the block is bored and the head dowelled to the block. Its not as easy as ordering something out of a cataloge. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 5, 2008 Share Posted September 5, 2008 I just checked and E85 has an octane rating of 105. I'd suggest you stick to closer to 12:1 compression, I think 14:1 is going to leave you pinging like crazy. You might try to see what high compression race engines run for fuel and work the problem from the other end. E Production L24's run somewhere around 12:1. You might see what octane fuel they're running. 1 fast z is right though, those 9 cc dome pistons are not a slap them in and run it type of thing. Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 5, 2008 Share Posted September 5, 2008 We run the ERC Spec Fuel at Bonneville and El Mirage, and it's 110+ Leaded. And we run 14.75:1 CR on that. Quote Link to comment Share on other sites More sharing options...
z3r0n3 Posted September 5, 2008 Author Share Posted September 5, 2008 12:1 would almost be attainable with just 89mm flat tops...unless i'm doing something wrong. Also, where can i find a good metal gasket for the L28? I've heard of the fel-pro and the hks ones, but i can't find them on websites? found a fel-pro on autozone, but it didn't say if it was metal, or what the compressed height was... Quote Link to comment Share on other sites More sharing options...
Careless Posted September 5, 2008 Share Posted September 5, 2008 but i think that those might protrude the gasket. Sorry, but... what? most domed pistons would do that. the domes are angled or relief cut to avoid PTV contact. anyway, have you considered measuring your current head's chamber volume with the intended spark plugs, and then finding out the other parameters/variables required to make an accurate calculation of attained compression with various combos of pistons? I know the L-Engine program does this, but heads and blocks vary to casting... so you may wanna check on that. I think with 12:1 or 13.5:1 you would be safe incase u get a horrible mix of ethanol somehow. in that case you may want to run a J&S Safeguard too. Quote Link to comment Share on other sites More sharing options...
z3r0n3 Posted September 6, 2008 Author Share Posted September 6, 2008 Wow! thanks for all the advice, I appreciate it! Its safe to say i'd have to do a mock-up reguardless. BTW, forgive my n00bness, but what's a J&S Safeguard? Also, any tips on the gasket? Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted September 6, 2008 Share Posted September 6, 2008 http://www.jandssafeguard.com/ it's a knock detection/prevention system from the looks of it. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted September 6, 2008 Share Posted September 6, 2008 Try these guys for your headgaskets. http://www.zccjdm.com/catalog.php/azcarbum/dt43033/pd858312/KAMEARI_L6_METAL_HEAD_GASKETS_ Quote Link to comment Share on other sites More sharing options...
woldson Posted September 6, 2008 Share Posted September 6, 2008 As a BTW, get take lined and no natural rubber, e85 will have that for lunch. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 6, 2008 Share Posted September 6, 2008 As a BTW, get take lined and no natural rubber, e85 will have that for lunch. Also, no brass and no bare aluminum in the fuel system. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted September 6, 2008 Share Posted September 6, 2008 Also, no brass and no bare aluminum in the fuel system. So I guess that means my aluminum fuel rail will have to go....? Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 6, 2008 Share Posted September 6, 2008 So I guess that means my aluminum fuel rail will have to go....? Not necessarily. I just had mine anodized - it wasn't that expensive and they turned it around in just a couple of days. Quote Link to comment Share on other sites More sharing options...
z3r0n3 Posted September 8, 2008 Author Share Posted September 8, 2008 any other reccomendations for headgaskets? kameari has always been a bit expensive.. Quote Link to comment Share on other sites More sharing options...
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